It has been more and more popular for people to use electrically motorized bicycles for commuting, which typically uses an electric motor to assist manpower. Such an electric bicycle seeks to reduce a workload required of a person by providing a bicycle with an electric motor, a battery for supplying the motor with power, and a prescribed motor auxiliary power in accordance with a control command from the bicycle rider. The motor auxiliary power is particularly useful for bicycle travelling of long-distance and/or long-duration, and travelling over undulating terrain.
Nonetheless, known motorized driving devices for bicycles and their installation may require extensive modification of the frame structure of the bicycle in order to mount the motor, battery and controls to the bicycle. The modifications required range from a radical redesign of the frame and transmission, to a large and ungainly addition to the front, rear wheel or some other part of the bicycle frame. The vast majority of these known mechanisms are not particularly useful or convenient for modifying an existing bicycle, such as those manufactured and sold by traditional bicycle vendors.